As technology progresses, more and more electronic products have been developed. Designs of electronic products have been focusing on miniaturization in response to market demands for high performance and high convenience. Miniaturization of the electronic products are mainly achieved by using large numbers of small-scaled electronic components, such as chips, diodes, transistors or light-emitting diodes made of semiconductor materials, in the internal circuits thereof. Therefore, fin field-effect transistors (FinFETs) have been developed for for improving performance of electronic components. As compared with conventional planar field-effect transistors (planar FETs), FinFETs include multiple control gates, so that components with greater performance and low power consumption can be designed. In conventional planar FETs and FinFETs, however, silicon substrate is used in conventional manufacturing methods and structures as a current channel; therefore, a bottleneck exists in simultaneously maintaining performances and reducing the size of semiconductor devices.
Since two-dimensional materials have layered structures, two-dimensional materials, especially the most well-known material “graphene”, show high electron mobility and low resistivity, and have resistance lower than copper or silver. Therefore, two-dimensional materials are considered as materials having the smallest resistance in the world, and are suitable for developing thinner and more conductive sub-10 nm electronic components or metal wires. Although graphene has many good physical properties, energy band of graphene has no energy gap, hindering its use as channel layers in semiconductor devices. The idea of using novel two-dimensional materials (e.g. transition metal dichalcogenides) other than graphene to form channel layers has been proposed, aiming to utilize the weak van der Waals bonding between layers of the two-dimensional materials to increase the possibilities of two-dimensionalization of channels for further industrial applications. As good semiconductor characteristics are required, candidates of the two-dimensional materials are very limited and fabrication using the two-dimensional materials also encounters difficulties. Although the academia and industry have been focusing on research and development of the materials, film growth characteristics of the two-dimensional materials affect the formation of a complete or large two-dimensional film layer and application thereof to an entire wafer surface during fabrication; therefore, the materials could not applied to existing fabrication processes. Although the academia have developed a lift-off process that completes the fabrication of transistors by presetting the locations and sizes of transistors so as to allow two-dimensional materials to be disposed at locations in which channels are to be formed, such approach is not only cost ineffective but also poor yielded, and most importantly, unable to be applied to production lines for mass production.
Accordingly, the application of two-dimensional materials in current technology is yet underdeveloped. Therefore, there is a need to provide manufacturing methods and structures having higher yield and applicable to existing processing fabrication technology and production lines for mass production.